Metrohm tiamo 2.4 Manual - Manual (Page 473)

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5 Method
tiamo 2.4
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5.6.3.2 DET
5.6.3.2.1 DET - Overview
Menu item: Method ▶ Insert ▶ New command...
Command for Dynamic equivalence point titrations.
Principle
With this command titrations with dynamic incremental reagent addition
are carried out. The volume increments vary as a function of the slope of
the curve. An attempt is made to reach constant measured value changes
with each dosing. The optimal volume for dosing is determined from the
measured value changes of the previous dosings. Measured value accep-
tance is drift-controlled (equilibrium titration) or after a waiting time.
NOTE
As the reagent dosing in DET depends on the measured data, the titra-
tion curve should not deviate too much from an s-shaped curve.
Evaluation
Equivalence points EP are determined automatically in a similar manner to
that described in the Tubbs method (C.F. Tubbs; Anal. Chem 26 (1954)
1670–1671, quoted in Ullman 5 (1980) 659). The volume value of the
equivalence point VE is shifted from the inflection point towards the
smaller circle of curvature for real asymmetric titration curves.